What is the voltage of the motor when a centrifugal pump is operated with variable frequency?
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Does the voltage keep the voltage-to-frequency ratio constant?
The electromagnetic torque of any motor is the result of the interaction between current and magnetic flux; the current must not exceed its rated value, otherwise it will cause the motor to overheat. Therefore, if the magnetic flux decreases, the electromagnetic torque also decreases, resulting in a reduced load-carrying capacity. As can be seen from the formula E=4.44*K*F*N*Φ, during variable-frequency speed control, the magnetic circuit of the motor changes over a considerable range as the operating frequency fX varies; this makes it very easy for the motor’s magnetic circuit to become severely saturated, resulting in severe distortion of the excitation current waveform and the occurrence of sharp peaks with very high values. Therefore, the frequency and voltage must change proportionally; that is, while changing the frequency, the output voltage of the inverter is controlled to keep the magnetic flux of the motor constant, thereby preventing weak magnetism and magnetic saturation. This control method is commonly used in energy-saving frequency converters for fans and pumps.
The explanation upstairs was great; I’ve learned it. :victory:
The senior explained it very well, thank you
I’ve learned something; thank you so much! ! ! ! !